From the earliest days of residences, the use of a peephole allowing the occupants to view the exterior area adjacent of the door has been present. Typically such wickets or peepholes have a small diameter opening through the door and commonly a spherical or "fisheye" lens at the outer side. Such devices allow the occupant to observe the area in front of and around the door and usually maintain a degree of privacy while giving a highly distorted view of the off axis region. Examples of such devices are shown in the following patents:
U.S. Pat. No. 4,561,116, Dec. 24, 1985, Guy Neyret; PA1 U.S. Pat. No. 2,028,108, Jan. 14, 1936, H. Sklar; PA1 U.S. Pat. No. 2,262,203, Nov. 11, 1941, L. G. Redstone et al; PA1 U.S. Pat. No. 2,064,963, Dec. 22, 1936, C. E. Wheeler; PA1 U.S. Pat. No. 2,581,234, Jan. 1, 1952, A. Bloom; PA1 U.S. Pat. No. 2,638,810, May 19, 1953, G. H. Berleme
A number of devices have been developed for providing security from view including half silvered mirrors as disclosed in the Neyret patent identified above. In certain cases a shutter has been present on the interior face of the wall, which shutter remains closed at all times except when the occupant desires to view the exterior of the door. An example of such a shutter is shown in the Sklar patent, referenced above. Usually such wickets or peepholes, no matter how well designed, tend to present an unattractive exterior to the door. Likewise wickets or peepholes are usually fully obscured or fully visible but lack any type of control of the quantity of light passing through the optical system.